This program runs the Sieve of Erathostenes benchmark
This program is a part of the companion code for Core Java 8th ed.
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* This program runs the Sieve of Erathostenes benchmark. It computes all primes up to 2,000,000.
* @version 1.21 2004-08-03
* @author Cay Horstmann
public class Sieve
public static void main(String s)
int n = 2000000;
long start = System.currentTimeMillis();
BitSet b = new BitSet(n + 1);
int count = 0;
for (i = 2; i <= n; i++)
i = 2;
while (i * i <= n)
int k = 2 * i;
while (k <= n)
k += i;
while (i <= n)
if (b.get(i)) count++;
long end = System.currentTimeMillis();
System.out.println(count + " primes");
System.out.println((end - start) + " milliseconds");
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